ew Publication Pattern and Format
Beginning with the 2002 edition, the NLM Classification is published in
electronic form and updated annually. The online environment offers many advantages to users
including hyperlinks between class numbers in the index and the schedules, between terms within the index,
and links from "MeSH Tree icons" in the Index to the term in the Medical Subject
Headings (MeSH®) Browser.

The development of the online data creation and maintenance system used to produce this
edition of the Classification gives NLM the ability to update it annually in tandem with MeSH.

The NLM Classification is available for downloading in HTML at http://www.nlm.nih.gov/class.
Publication of printed editions ceased with the 5th revised edition, 1999.

Scope of Revision
The 2002 edition incorporates all additions and changes to the schedules since 1999. New class
numbers were added as needed to reflect changes in MeSH and the biomedical and related sciences literature cataloged.
Class numbers added and deleted are given below. The Index was updated with appropriate MeSH concepts through 2002.

The outlines of all schedules were systematically reviewed and revised, and new ones were developed
for schedules where none existed. These outlines provide the user with a quick overview of a schedule's
content and assist in maneuvering through one.

Class number names were revised to reflect changes in MeSH application and practices as well
as changes in MeSH itself. For example:

The class name "Hemodialysis" was replaced with the MeSH concept "Renal Dialysis"

The term "Nomenclature" was deleted from all class names because it is now a see reference to "Terminology" in MeSH

Prepositional phrases used as class names were simplified, e.g., "Nursing of diseases of the respiratory system"
became "Respiratory system nursing"

The following is a list of class numbers added to the 2002 edition of the NLM Classification.

New Number

Class Name

Previously Classed In

QV Pharmacology

QV 325

Antioxidants

QV 800

QW Microbiology and Immunology

QW 45

Microbial drug resistance

QW 52

QW 168.5.F5

Flaviviridae

QW 168

QZ Pathology

QZ 52

Genetic techniques

QH 441

W Health Professions

W 74.1

General coverage (Not Table G)

W 74

WA Public Health

WA 295

Disasters. Disaster planning. Rescue work. Terrorism

Various numbers

WA 487.5.H4

Health personnel

WA 487

WB Practice of Medicine

WB 60

Bioethics. Clinical ethics. Clinical ethics committees

QH 332

WB 369.5

Specific techniques, A-Z

WB 369

WB 369.5.A17

Acupressure

WB 369

WB 369.5.A18

Acupuncture Analgesia

WB 369

WB 369.5.E2

Ear acupuncture

WB 369

WB 369.5.E4

Electroacupuncture

WB 369

WB 369.5.M5

Meridians. Acupuncture points

WB 369

WB 369.5.M9

Moxibustion

WB 369

WD Disorders of Systemic, Metabolic or Environmental Origin, etc.

WD 200.5.H5

Hyperammonemia

WD 200

WD 200.5.M6

Mitochondrial diseases

WD 200

WG Cardiovascular System

WG 141.5.M2

Magnetic resonance imaging

WG 141

WY Nursing

WY 159.5

Family nursing

Various numbers

WZ History of Medicine

WZ 65

21st century

None

WZ 112.5.A2

Allied health personnel

WZ 112

WZ 112.5.B3

Biologists

WZ 112

WZ 112.5.D4

Dermatologists

WZ 112

WZ 112.5.G2

Gastroenterologists

WZ 112

WZ 112.5.P15

Parasitologists

WZ 112

WZ 112.5.P3

Pediatricians

WZ 112

WZ 112.5.R2

Radiologists

WZ 112

The following is a list of class numbers deleted from the 2002 edition of the NLM Classification.